Chest tubes are medical devices commonly used to drain unwanted air or fluid from the space surrounding the lungs. Historically, a technique called “milking” or “stripping” was employed to maintain the tube’s patency, aiming to prevent blockages and ensure continuous drainage. However, modern medical understanding and evidence have led to a re-evaluation of this practice.
Understanding Chest Tubes
A chest tube is a hollow, flexible catheter inserted into the pleural space, the area between the lungs and the inner chest wall. This space normally contains a small amount of fluid, allowing the lungs to glide smoothly during breathing. The pleural space maintains negative pressure, which is essential for lung expansion.
When air, blood, or excess fluid accumulates in this space, it can compromise lung function, potentially leading to a collapsed lung (pneumothorax), blood in the chest (hemothorax), or fluid buildup (pleural effusion). Chest tubes are inserted to remove these substances, re-establish negative pressure within the pleural space, and allow the lung to re-expand. The tube is connected to a closed drainage system that collects the drained material and prevents air or fluid from re-entering the chest.
What is Chest Tube Milking?
Chest tube milking, also called stripping, is a manual technique once used to clear potential obstructions within the tube. This involves compressing the tube near the patient’s chest and then, with the other hand, sliding continuous pressure along it towards the drainage system. The aim was to dislodge clots or thick fluid and promote drainage. This physical manipulation differs from gentle tapping or shaking of the tube, which may be performed under specific protocols.
Why Milking is No Longer Recommended
Routine chest tube milking or stripping is discouraged in modern medical care due to potential risks and a lack of proven benefit. Compressing and releasing the tube creates significant negative pressure within the chest, sometimes as high as -100 to -400 cm H2O. This excessive suction can pull lung tissue into the tube’s drainage holes, causing trauma or bleeding.
The mechanical manipulation can also dislodge clots that might have been forming a seal, potentially leading to new bleeding or allowing air to enter the pleural space. Studies show that milking does not consistently improve drainage volume or prevent tube occlusion. Some research suggests milking can increase pleural fluid drainage by stimulating the pleura, but this does not indicate improved patient outcomes.
Current Best Practices for Chest Tube Care
Current best practices for chest tube management focus on maintaining a closed and patent drainage system through less invasive methods. Healthcare providers ensure the drainage system remains below the patient’s chest level to facilitate gravity drainage and prevent backflow. Tubing is routinely inspected for kinks, occlusions, and dependent loops, which can impede drainage and increase intrathoracic pressure.
Monitoring drainage characteristics, such as volume, color, and consistency, is a continuous process. Gentle manipulation, like light tapping, may be considered in specific situations to encourage drainage, but aggressive milking or stripping is avoided. The emphasis is on proper tube positioning, patient mobility when appropriate, and using continuous or intermittent suction as prescribed. If drainage issues persist, assessment for tube malfunction or patient repositioning is prioritized over forceful manual clearing.